506 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



VARIOLA ; SHEEP POX. 



In the early part of the last century, variola was a formidable 

 plague of the flocks of Europe. In 1819 over a million sheep died of 

 this disease in France alone, and in 1823 half a million in Austria. 

 In some European countries it is still prevalent. This disease bears 

 an interesting relation with cow pox in cattle and smallpox in man. 



Causes. Variola is a highly contagious disease, the contagious 

 element being present in the crusts from the pustules on the skin, in 

 the excretions, blood and expired air. It can be carried a long dis- 

 tance. The exact nature of the virus is not known. In sheep sheds, 

 yards, etc., the virus may remain active for a month or six weeks, but 

 is easily destroyed by putrefaction, a high temperature and the ordi- 

 nary disinfectants. Variola is spread by animals that have had it 

 within a period of a few weeks or a month, by innoculated sheep, 

 wool, dogs, manure, fodder, etc. One attack causes a life-time im- 

 munity. The period of incubation is from four to seven days. 



Symptoms. The sheep is depressed, weak, hangs its head, 

 breathes quickly, is feverish and has chills. In a day or two red 

 spots or pimples appear on the skin not covered or incompletely cov- 

 ered with long wool. When the eruptions are close together the skin 

 becomes badly swollen. In about five days the vesicles or pustules 

 form, dry up and scab over, the swelling then disappears and the 

 scabs loosen and drop off leaving a pit in which no wool afterwards 

 grows. As a prevention, healthy animals are given a mild form of 

 the disease by inoculating them on the ear, tail, etc., with a virus ob- 

 tained from a mild case after it has run for six or eight days. 



SYMPTOMATIC ANTHRAX; BLACK LEG. 



Causes. This is not a common disease of sheep. The specific 

 cause is a germ, a bacillus that when conditions are favorable will 

 probably develop in the soil and live for years. The germ gains en- 

 trance to the body by some wound on the leg, mouth or body. The 

 period of incubation is from one to five days. 



Symptoms. The tumors may develop on different parts of the 

 body, develop rapidly and are sensitive at first. The skin over the 

 tumor soon becomes gangrenous and cold, and when cut into the 

 tissues are dark colored and a frothy, red liquid together with gas 

 escapes. The general symptoms are loss of appetite, weak pulse, high 

 temperature and finally difficult respiration, violent colic, brain com- 

 plications, coma, insensibility and death. The disease runs a rapidly 

 fatal course. 



Treatment. This is purely preventive. When the disease is 

 present in a flock, vaccination should be practiced. 



ANTHRAX ; CHARBON ; CARBUNCLE. 



Anthrax has been known for centuries, but it has been only 

 within the last fifty years that its true character was discovered. In 

 this country the disease is not very prevalent and is not common 

 among sheep. 



Causes. The specific cause of this disease is a bacillus, the bacil- 

 lus of anthrax. Outside of the body this germ will grow and multiply 

 whenever the conditions are favorable, and it will resist to a remark- 



